Studies towards complex bridged alkaloids: regio- and stereocontrolled enolate chemistry of 2,5-diketopiperazines
作者:Mark Pichowicz、Nigel S. Simpkins、Alexander J. Blake、Claire Wilson
DOI:10.1016/j.tet.2008.02.020
日期:2008.4
N-protected diketopiperazines (DKPs) via enolate intermediates has been studied. The enolate reactions were highly diastereocontrolled, leading to enantiopure DKP products if chiral amino acid precursors were employed, and giving racemic products, starting with centrosymmetric DKPs, even when a chiral lithium amide base was used to generate the lithium enolate. With unsymmetrical DKPs derivedfrom proline
Synthesis towards complex bridged alkaloids derived from diketopiperazines: a cationic cascade approach to stephacidins, paraherquamides and related systems
作者:Mark Pichowicz、Nigel S. Simpkins、Alexander J. Blake、Claire Wilson
DOI:10.1016/j.tetlet.2006.09.046
日期:2006.11
Regioselective enolate formation, followed by stereoselective electrophilic quenching of unsymmetrical proline-derived diketopiperazines (DKPs), enabled the synthesis of variously substituted DKPs, including one substrate which could be further substituted and cyclised to give the bicyclo[2.2.2]diazaoctane core structure present in paraherquamide and stephacidin natural products.